Will wonders ever cease? The Weather Channel is allowing for some truth regarding hurricanes? Well, sure, it’s incomplete, but, it’s a baby step.
From the Weather Channel we see this …..
Well, yes, the title may mislead some people. TWC is referring to the North Atlantic basin only. But, let’s put up what they’re showing.
If the Atlantic hurricane season ended now, this would be the least active Atlantic season in 30 years.
Yes, there have been 11 named storms through Oct. 11, only one storm shy of the 30-year average of 12 named storms. However, that doesn’t tell the whole story.
A better method of summing up hurricane season activity than simply counting storms utilizes the Accumulated Cyclone Energy, or ACE, index. This is calculated by adding each tropical storm or hurricane’s wind speed through its life cycle. Long-lived, intense hurricanes have a high ACE index. Short-lived, weak tropical storms, a low ACE index. Summing up the ACE indices of each storm or hurricane will give you an ACE index for the entire season.
The bar graph at the top from Weather Underground shows just that. Notice the paltry total of 28, so far, in 2013.
According to Erika Navarro, Ph.D. candidate at the University of Washington, there were only two other seasons with equal or less activity in the Atlantic Basin since 1981:
That stretch from 1982-83 was one of the strongest El Niño events on record. Increased wind shear during stronger El Niño events tends to suppress tropical cyclone development. Indeed, only 10 named storms formed during the 1982 and 1983 seasons, combined, though one was destructive Hurricane Alicia. In 2013, we are currently in a neutral state, neither El Niño, or its opposite, La Niña.
There are, of course, other qualifiers. The season in the North Atlantic isn’t really over. TWC points out that we can expect more ACE accumulation for the year. And, before we go any further, ACE values are only a metric. They aren’t wholly adequate to define the force of a hurricane or a hurricane season. Still, it seems to be the current standard.
The only real complaint I would have about this is the obvious omission of the rest of the information. Any real curious reader would ask about the rest of the world. TWC is leaving this out. Maybe they don’t know how to find out the rest of the story. Or maybe they don’t think it is important. Or maybe they just don’t want you to know. It’s probably that they’re not very bright. I mean, they did ask someone who isn’t even a PhD, yet. Personally, I would have tried to contact Dr. Maue. He tweets about storms, constantly! Among many other things. So, ’82 and ’83 had lower ACE values than this year, ….. in the north Atlantic basin.
Here’s the Northern and Southern Hemisphere’s yearly ACE values (Jan-Dec). Note that the SH’s season doesn’t run on that time scale, so other evaluations of annual ACE values may differ a bit.
In all likelihood, the NH ACE will be lower than any other over the last 30 years. And, could be the 2nd lowest in the entire data set. Knowing the readers’ thirst for knowledge and completeness, here’s a graph totaling the Global ACE values over the same time period.
So much for the “active” hurricane season NOAA said we would have.